Spinning Precious Metal out of Hot, Thin Air
Miners have always worked under tough conditions, but in a volcano? Russian scientists are doing so in an effort to capture rhenium--a very rare, highly durable metal used in high-stress environments such as satellites, jet engines, and gas-fired turbines. The Russians are extracting the metal from noxious gases belching from a volcano in the Kuril Archipelago, north of Japan.
Mikhail A. Korzhinskii, a scientist at the Institute of Experimental Mineralogy in Chernogolovka, 30 miles north of Moscow, and his colleagues have known since the early 1990s that the Kudriavy volcano spits up a few grams per day of rhenium sulfate, which is 77% rhenium by weight. But some of the rheniite, as it has been dubbed, escapes as gas. About six micrograms are lost in each liter of vapor that vents away--and at $1,450 per kilogram, that's nothing to sneeze at. So Korzhinskii's team plans to cap the vent with an insulated wooden dome and capture the rhenium using a filter made of zeolite, an absorbent natural mineral. Their goal is to recover two tons a year, or nearly $3 million worth. If it works, this would add 4% to worldwide production levels of rhenium--and just when demand for it is growing.
Tom A. Millensifer welcomes all this superheated air. A technical adviser at Rockford (Ill.)'s Powmet Inc., the leading U.S. distributor of rhenium, he says: "I was invited to go there several years ago and thought: `You have to be crazy to think about going to the edge of an active volcano."' Now, he says, "it seems like what they're doing could be feasible."By Petti FongReturn to top
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